Examination GetExamination(ZAP billCase, int examinationStage)
        {
            var examination = new Examination();

            if (examinationStage == 1)
            {
                examination.BeginDate = billCase.Z_SL.SL.USL.First(x => x.CODE_USL == 24101).DATE_IN;
            }
            else
            {
                examination.BeginDate = billCase.Z_SL.SL.DATE_1;
            }

            examination.EndDate = billCase.Z_SL.SL.DATE_2;

            examination.HealthGroup = GetHealthGroup(billCase.Z_SL.RSLT_D);

            var naz_r = billCase.Z_SL.SL.NAZ.FirstOrDefault()?.NAZ_R ?? 0;

            examination.Referral = GetRefferal(examination.HealthGroup, naz_r);

            return(examination);
        }